1. Technical Field
The present invention relates in general to an improved digital storage system. In particular, the present invention relates to a method and system for preventing data loss due to hard disk drive failures. More particularly, the present invention relates to an improved method and system for detecting a precursor to a potential hard disk drive failure prior to any detectable degradation in drive functional performance. Still more particularly, the present invention relates to utilizing signature fluid dynamics within a hard disk drive fluid bearing to determine that corrective action is necessary to protect customer stored data.
2. Description of the Related Art
Generally, a digital data storage system consists of one or more storage devices that store data on storage media such as magnetic or optical data storage disks. In magnetic disk storage systems, a storage device is called a hard disk drive (HDD), which includes one or more hard disks and an HDD controller to manage local operations concerning the disks. Hard disks are rigid platters, typically made of aluminum alloy or a mixture of glass and ceramic, covered with a magnetic coating. Typically, two or three platters are stacked vertically on a common spindle that is turned by a disk drive motor at several thousand revolutions per minute (rpm).
The demand for increased speed and storage capacity has resulted in ever faster and more compact hard disk drive assemblies. Modern disk drives typically have several stacked disks that spin on a shaft at speeds exceeding 10,000 rpm. The track densities on these disks are often more than 12,000 tracks per inch (tpi). Traditional spindle motors consisting of a shaft supported by ball bearings have inherent shortcomings in light of the faster, more compact modern HDD""s. Some of the problems encountered by such ball bearing spindles include non-repeatable run out (NRRO), limited grease life, and inherent ball bearing noise.
A solution to some of the problems associated with ball bearings has been to replace them with hydrodynamic or fluid bearings. The liquid film within a fluid bearing provides superior damping which results in less NRRO and a quieter motor. The motor""s resistance to shock and external vibration is also improved.
A number of known storage subsystems incorporate certain techniques and devices to predict storage device failures, along with other techniques and devices to protect data from being lost or corrupted by such failures. Data storage systems, such as hard disk drives, commonly employ Predictive Failure Analysis (PFA) as a self-diagnostic tool. PFA is usually implemented via micro-code instructions that control drive assemblies. The main purpose of PFA (sometimes referred as Self-Monitoring, Analysis and Reporting Technology, or xe2x80x9cSMARTxe2x80x9d) is to issue warnings to users that the hard disk drive is deteriorating and may xe2x80x9ccrashxe2x80x9d. PFA is implemented by performing periodic self-diagnostic tests. For example, PFA may be utilized to measure and compare current parameter values against those stored at the time of manufacture. PFA may also be utilized to examine the time rate of change of HDD performance parameters. An example of such a parameter is resolution, which is correlated to the fly height of a magneto-resistive (MR) head. Consistent with current implementations of PFA, a detected increase in resolution beyond some pre-determined threshold may trigger a PFA warning.
Current implementations of PFA utilize several electromechanical performance parameters within a HDD. These parameters include magneto-resistive (MR) head fly height and Read/Write signal amplitude and resolution. Although current implementations of PFA are intended to warn a system or a user prior to a drive failure that results in loss of user data, the parameters currently serving as failure precursors are directly indicative of the quality of drive operations. Therefore current implementations of PFA are limited to detecting imminent failures with potentially catastrophic loss or corruption of user data.
It would therefore be desirable to provide an improved method and system that would allow the drive control circuitry to monitor a precursor to HDD failure that is itself unrelated to actual drive operability. Such a method and system, if implemented, would be useful by leveraging existing drive error prediction and recovery tools such as PFA and SMART so that potential drive failures may be diagnosed and corrected well before any degradation in drive performance occurs, thus providing maximum protection to user data.
It is therefore an object of the invention to provide a method and system for improving a digital storage system.
It is another object of the invention to provide an improved method and system for preventing hard disk drive failures.
It is still another object of the invention to provide an improved method and system for detecting a potential hard disk drive failure prior to any detectable degradation in drive functional performance.
It is yet another object of the invention to provide an improved method and system that utilize signature fluid dynamics within a hard disk drive fluid bearing to determine that corrective action is necessary, and undertaking such corrective action, thereby protecting customer data.
The above and other objects are achieved as is now described. A method and system within a data processing system for predicting failure of a hard disk drive having a fluid bearing during runtime operation of said hard disk drive, wherein said fluid bearing has an established signature dynamic fluid response, are disclosed. First, a runtime vibration level of the fluid bearing is measured. This runtime vibration level is translated into a runtime dynamic fluid response which provides an indication of the operating condition of the fluid bearing. The runtime dynamic fluid response is compared with the baseline dynamic fluid response in real-time during operation of the hard disk drive. Finally, in response to a predetermined departure of the runtime dynamic fluid response from the baseline dynamic fluid response, a protective response is initiated, such that data loss within the data storage system due to fluid bearing failure is prevented.